The present invention relates generally to systems for multi-function control and display, and more particularly to a display based cursor system for implementing fully coupled display and cursor selection of a plurality of interactive and non-interactive displays of an aircraft flight deck.
The increasing trend on aircraft flight decks has been towards the use of more complex and numerous display and cursor based interactive functions. The display environments within various vehicles such as commercial and military aircraft will likely become even more display intensive in the following years. On present day flight decks, multiple functions (e.g. Electronic Checklist, Data Link, Navigation, FMC interface, Airframe System interfaces, Engine displays, Status displays, etc) can be displayed on multiple displays. The trend toward greater numbers of displays is almost certain because the use of dedicated control panels is limited by space constraints and cost considerations.
In general, the potential for operator display misselections, unintended/inadvertent input errors, and increased workload are associated with multiple display activity. It is believed that the root cause of such problems is associated with display and cursor management designs which are sometimes problematic for pilot(s) to operate, require multiple reaching motions by the pilot(s) to select the proper display, and which can occasionally lead to difficulty in managing the selection and/or use of shared and dedicated displays.
There are currently only two interactive functions in use on the Boeing 777 aircraft: the Electronic Checklist (ECL) function and the Comm Management (COMM) function. The remaining functions are non-interactive information interacts such as the system synoptic and the secondary engine instruments page. The interactive ECL and COMM functions are seldom, if ever, used concurrently by the same pilot. When pilot activity is limited to one pilot and a single display, the errors reported and investigated are truly rare. However, even today, when multiple displays are called into concurrent use by the same pilot or both pilots, there is always at least a small chance for inadvertently selecting or deselecting an unintended display or function. More significantly, when the current multi-function display design is employed in a highly display intensive environment where more shared and dedicated displays and more interactive functions exist, the additional workload that results for the pilots, as well as the risk of misselections by the pilots, increases significantly.
As shown in FIG. 1, the Boeing 777 aircraft has three multifunction 8xe2x80x3xc3x978xe2x80x3 (20.32 cmxc3x9720.32 cm) displays, which are respectively Left 104, Center 110, and Right 108. A single glare shield located 5xe2x80x3xc3x975xe2x80x3 (12.7 cmxc3x9712.7 cm) display select panel (DSP) 102 is shared by both pilots and allows selection of the three multifunction displays. Display selection is mutually exclusive; only one display at a time can be selected. The desired one of several functions (e.g., Electronic Checklist, Data Link, Navigation display, Airframe system synoptic, Engine display, Status display, etc.) can then be selected to that display. Of the three multifunction displays, the Left 104 is currently dedicated exclusively to the left seat pilot, the Right 108 is currently dedicated exclusively to the right seat pilot, and the Center 110 is shared by the two pilots. A second center display 106 is dedicated to EICAS. Interface with these displays is via two 3xe2x80x3xc3x975xe2x80x3 (7.62 cmxc3x9712.7 cm) cursor control devices (CCDs) 113, 114 located on the center aisle stand. The left CCD 113 is dedicated to the left seat pilot and the right CCD 114 is dedicated to the right seat pilot. Switches 119 on the left CCD 113 allow the left cursor to be moved between the Left and Center multifunction displays 104, 110 without affecting the display selected on the DSP 102. Likewise, switches 118 on the right CCD 114 allow the right cursor to be moved between the Right and Center multifunction displays 108, 110 without affecting the display selected on the DSP 102.
Two types of system operating errors which have been noted are display misselection and input errors. Display misselections arise primarily because a user""s cursor can be active on one display while a different display is selected on the DSP. Users then subsequently attempt to deselect or select a function and that function deselection or selection ends up unexpectedly on a display other than the display they are usingxe2x80x94often displacing some other function. The user then has to recover both the unintended displaced function and the originally intended deselection or selection. In a high workload situation this can be extremely disruptive. Display misselections can arise whenever two or more displays are in concurrent use. The strategy used by pilots who generally manage to minimize such errors is to manually couple their cursor and display selection. At either the beginning or end of their interaction with a display, these pilots first select the display they are using on the DSP. While this manual coupling eliminates many of the potential display misselections, the cost is high in terms of added physical and cognitive workload. Display misselections can still occur when, under high workload, the pilot forgets to manually select the intended display before selecting or deselecting a function.
Input errors and increased workload arise primarily because of the shared display select panel (DSP). Because both pilots use the DSP, the DSP cannot tell which pilot is making DSP selections. In the case of the left multi-function display which is currently dedicated to the left seat pilot, and in the case of the right multifunction display which is currently dedicated exclusively to the right seat pilot, when these displays are selected the appropriate cursor (Left or Right) can be automatically placed on the display. This is known as xe2x80x9cdeterminantxe2x80x9d display and cursor coupling. However, in the case of the shared center display, the appropriate cursor is xe2x80x9cindeterminatexe2x80x9d because it is not known which pilot (left or right) is selecting from the shared DSP. The current Boeing 777 design is such that if one of the cursors (Left or Right) is active on one of the dedicated multifunction displays (Left or Right), then the opposite cursor will be automatically placed on the center display when an interactive function is selected to the center display. If neither one of the cursors (Left or Right) is active on one of the dedicated multifunction displays (L or R), then the last cursor that was active on the center display will be automatically placed on the center display when an interactive function is selected to the center display. This cursor coupling to the shared center display is appropriate only if the other pilot or last center display user is selecting the center display. This design is predicated on the assumption that the same user will not be interacting with two or more displays concurrently. It should be noted that this is an optimal design, given the current Boeing 777 design which has only two interactive functions, those being ECL and COMM, which are not generally used concurrently by the same pilot.
Input error problems occur when multiple displays are used concurrently. If the same user selects the shared display while their cursor is active on their dedicated display, the opposite cursor is automatically coupled to the shared display selection. In workload intensive environments or situations it is possible that this might cause confusion and/or frustration because previously, whenever the shared display is the only or first display a user has selected, his cursor has been coupled to that selection. In the case where the shared display is selected while the dedicated display is in use, user attempts to make an input on the shared display actually result in input actions on the dedicated display where their cursor remains. Users who avoid input errors invariably adopt the strategy of always selecting their cursor to the display of their focus. In effect, these users manually couple their cursor to their display selection. In summary then, manually selecting the intended display before selecting or deselecting a function eliminates display misselection and manually selecting the user""s cursor to the intended display before input eliminates input errors. However, both of these manual strategies are workload intensive and pilots often forget to do so under stress, when pressed for time, or when workload is high.
It is, therefore, a principal object of the present invention to provide a multifunction control and display management system for a flight deck of an aircraft, which virtually eliminates the possibility of pilot error in selecting desired displays or functions from one of a plurality of multifunction displays, as well as further reducing the potential for input errors by the pilot(s).
The above objects are provided by a multifunction control and display system incorporating improved cursor and display management. The invention eliminates or ameliorates display misselections, unintended/inadvertent control errors, and workload associated with multiple display activity, on a flight deck of an aircraft or in any location or application involving the use of multiple displays and functions.
In a first aspect of the invention, a plurality of displays and at least two cursor control devices are provided to display both interactive functions, non-interactive functions and a cursor. Each cursor control device (CCD) has a menu select switch on the CCD and a function control thumb-switch. In this aspect of the invention, the conventional display select panel (DSP) and the cursor select buttons on the CCD are not used. Instead, the cursor is moved from one display to another by simply pushing the cursor against a display edge leading to an adjacent display. The cursor is displayed full time in interactive functions, non-interactive functions, and on blank displays. Interactive and non-interactive functions are selected from a menu which appears on the display the cursor is on when the CCD menu select switch is pressed or when the cursor is placed in an inactive (e.g., unhighlighted) display area and the CCD thumb-switch is pressed. On certain displays or display formats, the menu which appears may actually be a control panel which allows interactive control of aircraft systems, components or interfaces. Alternatively, the menu which appears may allow selection and display of mini control panels which appear concurrent with the existing display format, that is, overlay only a part of the display format that was displayed prior to selection of the control panel. This allows the concurrent use of two or more functions (any of which may be interactive or non-interactive) on the same display.
In this xe2x80x9csingle display surfacexe2x80x9d aspect of the invention, the cursor may be moved freely between displays. In other cases, however, software may be employed to allow cursor operation at the edge of a display without unintended cursor movement between displays. For example, once the cursor reaches the edge of a display, additional time, force or other input may be required before the cursor transitions to the adjacent display. Alternatively, the user may be required to remove input to the cursor movement device or to operate the cursor movement device in a particular manner. For example, once the cursor is near or reaches the display edge, the user may be required to select the CCD thumbswitch to move the cursor to the next display, or untouch the CCD touch screen before a touch screen input causes the cursor to transition to an adjacent display. Alternatively, a certain rate of cursor travel may be required before the cursor transitions to an adjacent display. Still further, once the cursor reaches the display edge, the user""s finger could be required to travel a certain distance or at a certain rate on the CCD touchscreen before the cursor would transition to an adjacent display. Regardless of the specific means employed, the preferred embodiments reliably assure that movement of the cursor between displays is intentional and not accidental.
In an alternative embodiment of the invention, the cursor may move freely throughout 100% of the surface area of each display. As the cursor moves into active controllable areas in a display or display function, that active/controllable area may be highlighted in some visual (e.g., intensity, patter, color, flashing, etc.) or aural (e.g., tone, voice, etc.) manner. An alternative case is envisioned where the cursor is limited to the active/controllable areas on each display. In this case, the cursor would appear to xe2x80x9cjumpxe2x80x9d from one active/controllable area to an adjacent active/controllable area both within and between displays. As in transitions between displays, suitable means may be used to reduce or prevent unintentional cursor movement between active/controllable areas.
In another alternative preferred embodiment of the invention, a DSP and a CCD are provided. Multiple displays (e.g., left, upper center, lower center, right, etc) are selected from each user""s CCD. Display selection places the CCD cursor on the selected display. Interactive and non-interactive functions are selected from the DSP.
In another preferred embodiment the DSP is eliminated. Interactive and non-interactive functions are selected and deselected from an on-screen menu displayed by selecting the cursor to a display using the CCD buttons corresponding to each display and then pressing a CCD menu select switch. As a result, this configuration reduces part count, increases system reliability, and lowers change cost of the existing multi-function control and display system. It also reduces workload and increases error free management of and interaction with the displays by operators.
The preferred embodiments of the present invention thus reduce the potential operator confusion that might result in workload intensive situations or environments with previously developed multifunction display arrangements. Since cursor and display selection are integrated at each CCD, and since in most cases cursor, display and menu selections are coupled, there is virtually no risk of unintended display selections, deselections or unintended operator inputs.